This invention relates to data storage and, particularly, to secured data storage in solid state drives.
A solid state drive (SSD) is the non-elecromechanical (that is, “solid-state”) equivalent of the rotating, magnetic hard disk drive that is used for storage in almost all computing applications such as desk-top, laptop and notebook computers. The SSD uses non volatile solid-state memory such as flash devices, in place of rotating magnetic memories and therefore has no moving parts. Most SSDs use flash memory because it requires very low power when not being read or written to, and power can be turned off without data loss. Other forms of memory such as DRAM or SRAM require battery back-up to ensure persistence of data.
The typical SSD consists of a microcontroller, memory and some power management circuitry, and may or may not be internally encrypted. The SSD is provided with a standard interface, such as an Advanced Technology Attachment (ATA) interface, including Serial ATA (SATA) and Parallel ATA (PATA) (sometimes referred to as Integrated Drive Electronics (IDE) interface), ATA Packet Interface (ATAPI); a Small Computer System Interface (SCSI) or a Serial Attached SCSI (SAS); a Firewire interface; or a specialized interface for military and aerospace applications.
The conventional rotating disk hard drive is vulnerable to vibration and shock. An SSD can be made as rugged as any other electronic circuit without moving parts, and a principal advantage of the SSD is that it is much more rugged than a rotating hard-drive. In addition the SSD is faster and requires lower power. Disadvantages of SSDs principally include relatively high cost and lower data density. However, the cost per Gbyte for SSD storage is plummeting, and SSDs are now feasible in a greater number of applications. Within a few years, SSDs can be expected to replace magnetic hard disk drives in a large proportion of laptop and notebook computers.
Because of its ruggedness, SSD storage is ideal for deployment in harsh environments, and SSDs are a compelling choice for applications such as military, navy, aerospace, automotives, trains, oil drilling, etc. In these applications ruggedness usually overrides cost at some point so their acceptance here is happening more rapidly.
Data security is a major concern in hard drive data storage. Computers or hard drives may be stolen, or compact disks carrying data may be stolen or lost in transit. Results include misappropriation of proprietary information including technology and corporate strategic plans, invasion of privacy or loss of personal identity, and theft of funds. Data security is extremely important in military and aerospace applications, in homeland security, etc.
SSDs can be encrypted with software keys determined from user entered strings or biometric sources such as a fingerprint reader or retinal scanner.
In many situations sensitive data on the SSD needs to be protected. This is accomplished by either physical destruction of the media or through a secure erase operation. This is a procedure that writes a predefined data pattern over the media repetitively, guaranteeing that the existing data cannot be recovered through any means.